Organochlorine pesticide and metal residues in a cichlid fish, Tilapia, Sarotherodon (=Tilapia) alcalicus grahami Boulenger from Lake Nakuru, Kenya     

J.K. Kairu 《International Journal of Salt Lake Research》1999,8(3):253-266

29 specimens of a cichlid fishSarotherodon (=Tilapia) alcalicus grahami were collected from Lake Nakuru between September and October 1990 and samples of liver, kidney, muscle, brain and fat were removed for analysis of organochlorine pesticide and metal residues. Fat was extracted and the concentration of three lindane (BHC/HCH) isomers (alpha, beta andgamma), aldrin, heptachlor, heptachlor-epoxide, endrin, dieldrin, DDD, DDE and DDT was determined. Fish muscle samples were digested and the concentration of mercury, arsenic and cadmium was also determined. No residues of o,p¹-DDD, p,p¹-DDD, aldrin, endrin and dieldrin were detected. The highest residue concentration detected was 0.062 mg kg⁻¹ of p,p¹-DDT. The mean pesticide residue concentration levels were generally low. The [p,p¹-DDT]/[p,p¹-DDE] ratio of 1.22 indicated that the residues of the parent DDT compound exist in the Lake Nakuru ecosystem. There was a negative fish length: DDE concentration relationship. Similarly, there was a very weak negative relationship between arsenic concentration and length of fish. The concentrations of metal residues were considerably low. The median arsenic and cadmium concentrations were 0.03 mg kg⁻¹ and <0.1 mg kg⁻¹, respectively. The concentrations of mercury, with a median level of <0.01 mg kg⁻¹, were particulary low and did not approach a level that would give rise to public health concern. Metal and pesticide residue concentration in fish in 1970 and 1990 does not show a significant increase. From these results, Lake Nakuru is presently not exposed to heavy pesticide and metal contamination, but there is a gradual build-up of these residues in the biota.  相似文献   

Ionic‐Liquid‐Assisted Hydrothermal Synthesis of Ag/AgBr for Photodegradation of Imidacloprid under Visible Light     

Dandan Guo  Xiaoqing Zhu  Sheyun Chen  Cenling Wang  Mingli Pi  Xiaoxia Chen  Yuqing Shi  Jingtao Dai 《洁净——土壤、空气、水》2019,47(5)

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Effects of Planting Field on Groundwater and Surface Water Pollution in China     

Yaa Opoku‐Kwanowaa  Rachel Kasoro Furaha  Li Yan  Daming Wei 《洁净——土壤、空气、水》2020,48(5-6)

Water forms an essential resource for life on earth because all living things on earth depend on water for life activities. However, with the increase in the human population, which is coupled with intense urbanization and agricultural activities, global water pollution has increased over the past decades. In China, agricultural activities that occure mainly in the planting fields have been listed as the main source of surface water and groundwater pollution. This review focuses on the major factors that influence pollution from planting fields in China mainly as a result of farming activities such as flood irrigation, excessive application of fertilizers and pesticides, and poor management practices. At present, good results are achieved by adopting soil fertilization test formula, biodegradable pesticides, proper irrigation, and agroforestry interventions. In the future, pollution from planting fields as a non‐point source of water pollution can be improved and resolved by perfect nutrient management, best management practices, organic amendments, restoring water environment, and intelligent assessment management.  相似文献